1. Field of the Invention
The present invention relates to a video recording system, and more particularly, to an apparatus and method for compensating for the motion of the video recording system.
2. Description of the Related Art
When photographing an object using an image recording system, e.g. a camcoder, it is difficult to stably photograph the object without trembling of the hands. Such hand trembling may be serious when the image capturing system is small and light so that the user photographs with only one hand. Furthermore, as the magnification of the zoom lens of the camcoder increases, a photographed image is more seriously shaken by a minute movement of the camcoder.
In order to stabilize the captured image, a system controller of the video camera detects a local motion vector of an input video signal, estimates motion due to the trembling of the hands among the detected motion vectors, and determines the motion of the image for compensating the motion of the camera. Typically, conventional motion vector detecting methods employ the band extract representative points (BERP) technique or the edge-pattern matching technique.
In a motion detecting method using the BERP technique, a predetermined number of representative points are set in a motion detecting area. The representative points are passed through a bandpass filter to extract characteristic points. Then, the motion of the image is detected by use of the characteristic points. However, this method has drawbacks in that a filter is to be used to extract characteristic points and the required memory capacity may be increased.
A motion detecting method using the edge pattern matching technique detects motion of the image by converting the edge signal of an image into a binary image signal. Such a method can be implemented by a simple hardware and reduces the required memory capacity by extracting edge patterns from the image, and thus may overcome the problems of the method using BERP. However, according to this method, the detecting precision may be lowered when the illumination is low. Furthermore, it is difficult to detect the edge from the image.
Therefore, a motion detecting method which can reduce the required memory capacity, while maintaining the degree of precision in motion detection, is required.